Charge regulation by ferromagnetic metal/LiF spin-polarized interface for high-performance Li metal anodes

The interfacial characteristics of the Li metal anode (LMA) play a crucial role in its overall performance. Despite various materials being applied to modify the interface, a comprehensive understanding of their specific mechanisms remains to be investigated. Herein, we have prepared carbon cloth (CC) frameworks with their surfaces modified using ferromagnetic metal/LiF heterogeneous films (TM -LiF-CC) as the substrate for LMA, which exhibit superior electrochemical performance. Utilizing ferro-magnetic Co as a representative example, our study demonstrates that the enhanced performance of Co-LiF-CC, compared to bare CC, is attributed to the spin-polarized interface contributed by the Co/LiF heterostructure. Co and LiF play individual roles in redistributing electrons and Li+ to promote homogeneous Li deposition. Co nanoparticles play a crucial role in generating strong surface capacitance by storing electrons in spin-split bands, while LiF, with low surface diffusion barriers, ensures fast transportation of Li+. The Co-LiF-CC@Li electrodes deliver long lives of 7400 and 3600 h at 1 and 2 mA center dot cm(-2) in symmetric cells, respectively; moreover, they enable full batteries with high and durable capacities, particularly when the N/P ratios are low (3.3 or even 1.7).

Automated summary

The interfacial characteristics of the Li metal anode are crucial for its overall performance. Researchers have found that modifying the carbon cloth framework using ferromagnetic metal/LiF heterogeneous films can greatly enhance the electrochemical performance. The improved performance is attributed to the spin-polarized interface contributed by the Co/LiF heterostructure.